MARKETING SOUTHERN-GROWN SWEET POTATOES. 17 
UNITED STATES GRADES. 
Tentative grades for sweet potatoes were proposed by the United 
States Department of Agriculture in April, 1918. Two years later a 
few changes were made and the grades, as revised and recommended, 
were published in May, 1920, in Department Circular 99. The fol- 
lowing extract gives the specifications for U. S. Grade No. 1 : 
U. S. Grade No. 1 shall consist of sound sweet potatoes of similar varietal characteristics which are prac- 
tically free from dirt or other foreign matter, frost injury, decay, bruises, cuts, scars, cracks, and damage 
caused by heat, disease, insects (including weevils), or mechanical or other means. 
The diameter of each sweet potato shall not be less than one and three-quarter inches nor more than 
three and one-half inches, and the length shall not be less than four inches nor more than ten inches, but the 
length may be less than four inches if the diameter is two and one-quarter inches or more. 
In order to allow for variations incident to commercial grading and handling, five per cent by weight, 
of any lot may not meet the requirements as to diameter and length, and, in addition, six per cent, by 
weight, may be below the remaining requirements of the grade. 
Any lot in which the diameter is not less than one and one-half inches and which contains a greater per- 
centage by weight of sweet potatoes below one and three-quarters inches than is permitted in U. S. Grade 
No. 1, but which otherwise meets the requirements of such grade shall be designated as U. S. Grade No.l 
Medium. 
Any lot in which the length is not less than six inches nor more than twevle inches and which contains 
a greater percentage by weight of sweet potatoes above ten inches in length than is permitted in U . S. Grade 
No. 1, but which otherwise meets the requirements of such grade shall be designated as U. S. Grade No. 1 
Long. 
DEFINITION OF GRADE TERMS. 
"Practically free'' means that the appearance shall not be injured to an extent readily apparent upon 
casual examination of the lot, and that any damage from the causes mentioned can be removed without 
appreciable increase in waste over that which would occur if the sweet potatoes were perfect. 
"Diameter" means the greatest dimension at right angles to any portion of a central line running 
through the sweet potato from stem end to root end. 
"Free from serious damage" means that any damage from the causes mentioned can be removed with- 
out increase in waste of more than ten per cent by weight over that which would occur if the sweet potatoes 
were perfect. 
FIELD GRADING. 
It is a general practice throughout the South to grade sweet pota- 
toes in the field at harvest time, both for immediate shipment and 
for storage. If the grower intends to store in a cooperative house or 
arranges to sell to a commercial-house operator he is usually fur- 
nished containers in which to deliver his crop. Under instructions 
from the storage-house manager he supervises the field grading, 
which consists of sorting out the bulk of the undersized and over- 
sized roots, and those showing disease, cuts, bruises, cracks, and other 
easily detected damage. Those that remain are loosely placed in 
the containers and hauled to the storage house. 
Field grading, as practiced, saves time and reduces the expense of 
handling at the storage house, but it is not sufficiently well done in 
most instances to eliminate the necessity for regrading. Storage- 
house operators find so much variation in the grading of individual 
growers that it is often necessary to refuse to accept their deliveries 
or to regrade as the potatoes go into the house. 
GRADING PRACTICES AND DEVICES. 
Grading at the storage house is often done by negro laborers, who 
are paid by the hour or day. Portable grading tables are constructed 
by building frames of convenient height and fastening burlap over 
the tops. As the potatoes are delivered the containers are emptied 
on these burlap-topped tables, and the several graders sort out and 
pack for storage those that conform to grade requirements. Those 
that remain are dumped into containers and returned to the grower. 
It facilitates the work of the graders to nail boards to one side of the 
grading table in such a way that a platform is provided on which to 
place empty containers. The platform should be high enough for the 
top of the container to be level with the top of the grading table. The 
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